1. Field of the Invention
The present invention relates to a clock movement control system used on radio controlled clocks, and in particular to a new radio controlled clock movement control system that enables the synchronized adjustment of the hour, minute, and second wheels with high efficiency and self reset in a fast manner.
2. The Related Art
In conventional clocks, a mechanical movement is used to drive the hour, minute, and second wheels. A radio controlled clock, however, makes use of wireless transmission technology incorporating such as an RF signal receiving element, a signal processing element, and an automatic time correction element in the movement control circuit, so that the radio controlled clock can receive radio wave signals from a ground transmitter that gets the time from a standard time generator. Once the radio controlled clock has decoded the signals through the RF signal receiver, the clock uses that time information to synchronize the hour, minute and second hands in its own clock, so that the same clock time will appear on all radio controlled clocks receiving the same radio signals. Also, another function of the radio controlled clock is that it can be self-reset down to the seconds every hour on the hour, so there will be no time discrepancy at all on any one of the radio controlled clocks.
Referring to FIG. 1, the typical architecture of a radio controlled clock includes a micro antenna 11, RF signal receiver 12, a microcontroller 13, and a clock movement module 14. The RF signal receiver 12 receives the time information through the RF receiver 12. After signal decoding, the signals are passed to the microcontroller 13, which works through the clock movement module 14 to synchronize the hour, minute and second wheels. When the radio controlled clock is activated, the hour, minute, and second wheels are first self-reset, and then the microcontroller 13 receives the standard time information, and synchronizes the movement of the hour, minute, and second wheels. The clock movement module 14 employs a photoelectronic control unit to adjust the hour, minute, and second wheels when a self-resetting is initiated.
Conventionally, the radio controlled clock movement module only has a single motor to drive the second wheel into rotation, which, through a linking gear, in turn drives the minute wheel, and, the later, further through another linking gear, causes the hour wheel to rotate in succession. If a time checking is initiated every hour on the hour, for example at one o'clock, the hour, minute, and second wheels first have to be self-reset. A photo-electronic control unit is used to determine whether the hour, minute, and second wheels are all zero reset. In the worst case scenario, the second wheel has to rotate 660 cycles to bring the hour, minute and second wheels back to respective zero positions, which is a time-consuming process. Therefore, the new generation of clock movement uses two motors and a photoelectronic control unit in the clock movement module, which performs the self-reset in two sections independent of each other, where the first motor to control the rotation of the second wheel, and the second motor is to control the rotation of the hour/minute wheels. This two-motor clock movement control has out performed the one-motor control model, but the time required for self-reset could be further improved if the operation of the motor is optimized.